The aim is to put 8 coloured dots on the board so that no two dot
are in the same row, column, or diagonal. (fig. A)
Two or three red dots are given. Be carefull not to move the red dots during the game.
You have to supplement them with green dots to make an 8 dots pattern. (Fig. A)

The game rules:

Choose any of the numbers on the backside and bring up the red
slider until it is next to the number. The arrow near the number should be pointing in the direction of the red slider. (Fig. B)

You have to place a red slider next to occurrence of your chosen
level number. The letter next to the number tells you which column.